year = 2004
month = 3;
if month == 1 or month == 3 or month == 5 or month == 7 or month == 8 or month == 10 or month == 12:
    print('这个月有31天');
elif month == 4 or month == 6 or month == 9 or month == 11:
    print('这个月有30天');
elif month == 2:
        if year% 100 == 100:
            if year%400 == 0:
                print("29天")#闰年二月份的天数
            else:
                print("28天")
    else:
        print("30天")